POLYDIENES WITH REDUCED SOLUTION VISCOSITY
A 1,4-cis polydiene formed by polymerizing at least a 1,3-butadiene monomer in the presence of a lanthanide catalyst system and a bis-diene additive.
1 . A process for the synthesis of a 1,4-cis polydiene comprising the steps of:
polymerizing at least a 1,3-butadiene monomer in the presence of a lanthanide catalyst system and a bis-diene additive.
2 . The process of claim 1 , wherein the bis-diene comprises the formula:
where m+n is greater than 2; Y is a sulfur or other chalcogens.
3 . The process of claim 1 , wherein the bis-diene comprises the formula:
where m+n is greater than 2; and X is an aliphatic hydrocarbon group, a cycloaliphatic hydrocarbon, aliphatic perfluoro carbon, or an aromatic hydrocarbon or a combination thereof; silane or siloxane; phosphine or phosphine oxides; epoxide, ethylene oxides or propylene oxides group.
4 . The process of claim 1 , wherein the lanthanide catalyst system comprises a neodymium catalyst.
5 . The process of claim 4 , wherein the lanthanide catalyst system is prepared by (1) reacting a neodymium carboxylate with an organoaluminum compound in the presence of a conjugated diolefin monomer to produce neodymium-aluminum catalyst component, and (2) subsequently reacting the neodymium-aluminum catalyst component with an alkyl aluminum chloride to produce the neodymium catalyst system, wherein the neodymium catalyst is prepared at a temperature that is within the range of about −60° C. to about 150° C., wherein the organoaluminum compound is selected from the group consisting of trialkylaluminum compounds and dialkylaluminum hydride compounds, and wherein the molar ratio of isoprene monomer to neodymium ranges from about 5/1 to about 500/1.
6 . A 1,4-cis polydiene, the 1,4-cis polydiene being a reaction product of at least a 1,3-butadiene monomer in the presence of a lanthanide catalyst system and a bis-diene additive.
7 . The 1,4-cis polydiene of claim 6 , wherein the 1,4-cis polydiene has a Mooney viscosity (ML1+4 at 100 C) from about 40 to about 90.
8 . The 1,4-cis polydiene of claim 6 , wherein the mole ratio of monomer to a bis-diene range is from 4200 to 29000.
9 . A tire having a tread or carcass compound comprising at least the 1,4-cis polydiene of claim 6 .
10 . The 1,4-cis polydiene of claim 6 , wherein the bis-diene additive is bridged by an aliphatic hydrocarbon group, a cycloaliphatic hydrocarbon, aliphatic perfluoro carbon, or an aromatic hydrocarbon or a combination thereof.
11 . The 1,4-cis polydiene of claim 6 , wherein the bis-diene additive is bridged by sulfur, a chalcogen or a combination thereof.
12 . The 1,4-cis polydiene of claim 6 , wherein the bis-diene additive is bridged by silane or siloxane.
13 . The 1,4-cis polydiene of claim 6 , wherein the bis-diene additive is bridged by phosphine or phosphine oxides.
14 . The 1,4-cis polydiene of claim 6 , wherein the bis-diene additive is bridged by epoxide.
15 . The 1,4-cis polydiene of claim 6 , wherein the bis-diene additive is bridged by ethylene oxides or propylene oxides group.